To isolate contents from biological materials, it is generally necessary to open the cell membranes of the biological material. Various possibilities for this exist. In particular in sugar production, it is customary for sugar beets initially to be mechanically worked by cutting, grating or rolling. Slicing machines are generally used for processing sugar beets into pencil-thick cossettes. In the further course of the procedure, contents are extracted by thermal cell disintegration. This involves the cell membranes of the beet cossettes being denatured by the thermal influence, allowing isolation of the contents that are to be recovered. In addition, the process of electroporation has been known for several decades. By applying a voltage, it is possible to permeabilize the cell membranes. Following the electroporation, extraction is therefore possible.
DE 101 44 486 C1 describes a process for the disintegration of biological cells on an industrial scale with pulsed electric fields. The process described is performed by a reactor which is integrated in a process line. The processed-product or transporting line is flowed through in the region of the reactor by liquid, in order in this way to expose the biological material to the effect of the pulsed electric fields.
SU 100 57 58 A describes an electroporation process for biological material including beets. In the process described it is provided that, in a cutting apparatus, the beets are alternately electroporated and then cut.
DE 101 44 479 A1 likewise describes an electroporation process for whole beets. The process is carried out in a drum reactor. The drum reactor comprises a water-filled tank in which the drum can rotate. The beets to be electroporated are drawn by the drum through the water by means of fingers fastened to the drum. The electroporation is brought about by electrodes and counter electrodes that are respectively located on the bottom of the tank and on the drum.
Apart from the electroporation of whole beets, the electroporation of beet cossettes is also known.
SU 764 643 describes the electroporation of sugar beet cossettes. The electroporation is performed here by the cossettes being transported by means of a conveying installation, this conveying installation comprising a conductive belt.
Zagorulko (Zagorulko, A. Ya.; Novye Fiz. Metody Obrabotki Pishch. Produktivo, 1958, vol. 1, 21-27) describes an electroporation device for the electroporation of sugar beet cossettes. The device comprises two fluted rotors, which rotate in opposite directions and force the cossettes through a gap of 1 to 2 mm in which the electric field acts.
A disadvantage of the previous processes is that the installations described provide that the beets or beet cossettes for extraction are transported by forced conveyance by means of belts, rollers, conveying drums or the like. This forced conveyance has the effect that the beet cossettes break before extraction as a result of the considerable mechanical stress, and consequently are to a great extent damaged. This in turn leads to lower efficiency in the downstream extraction. Valuable contents to be isolated can be lost in this way.
Guily et al. (CITS Proceedings Madrid 2003, Intern. Commission for Sugar Technology, pages 303 to 315, published by A. Bartens, 2003) describes a further possibility for transporting beet cossettes into an electroporation installation. Accordingly, a mixture of cossettes and liquid is pumped into the electroporation device. However, this presupposes that the cossettes are largely in an individually separated state, in order to prevent blockage and clogging during transport. A disadvantage of this is that it means that a high packing density of the beet cossettes during the electroporation cannot be made possible. This correspondingly also has the consequence of lower extraction efficiency.